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Define the ports of AT89C51 as input or output.

I m using AT89C51 for digital clock, with external clock.

i want to set the port0-1-2 for parallel data, and port3 for serial data

the problem is to define the port as input or Output

Master Clock
------------------
port0 for input
port1 for output
port2 for output
port3 for output (to send serial data)

Slave Clock
------------------
port0 for output
port1 for output
port2 for output
port3 for input (to receive data)

please tell me how can i set the ports for input and/or as outpur

Parents

0 Micro Club over 16 years ago in reply to ImPer Westermark

Thanks to support me, ports0-3 are full 8-bit ports.

I m sending my source code please inform me any types of errors

I shell be very thankful to you.

org 00h

;Set up Timer 1
        MOV     IE, #0                  ; Disable all interrupt
        MOV     TMOD, #020h             ; Timer 1: Mode 2 (8-bit reload)
        MOV     TH1, #230d              ; Reload value for 1201, SMOD = 0
        MOV     TL1, #230d              ; Make first time-out correct
        ANL     PCON, #07fh             ; To make SMOD =0

;Set up serial ports
        MOV     SCON, #50h              ; Timer 1 : Mode 1 (vari baud) and set receive enable
        SETB    TR1                             ; Start timer 1
        mov r1, #6d
        mov r2, #91d
        mov r3, #63d
        mov r4, #63d

MainLoop:
setb p0.7

mov r7, #90d
        SubLoop:
        mov r6, #90d
                InnerSpot:
                        jmp DisplayData
                InnerSpot1:
                djnz r6, InnerSpot
        djnz r7, SubLoop

clr p0.7

mov r7, #90d
        SubLoop1:
        mov r6, #90d
                InnerSpot12:
                        jmp DisplayData
                InnerSpot11:
                djnz r6, InnerSpot12
        djnz r7, SubLoop1


jmp MainLoop

DisplayData:
mov C, p2.7
orl C, p0.7


        mov b, r1
   mov p2, b
JNC Skip1
        mov b, #254d
        mov p1, b
Skip1:
                mov b, #255d
           mov p1, b
        mov b, r2
   mov p2, b
JNC Skip2
        mov b, #253d
   mov p1, b
Skip2:
                mov b, #255d
           mov p1, b

        mov b, r3
   mov p2, b
JNC Skip3
        mov b, #251d
   mov p1, b
Skip3:
                mov b, #255d
           mov p1, b

        mov b, r4
   mov p2, b
JNC Skip4
        mov b, #247d
   mov p1, b
Skip4:
                mov b, #255d
           mov p1, b

        jnb RI, CheckReturnPoint
        clr RI
        mov a, sbuf

cjne a, #246d, CountCountinus
        mov r0, #0d

CheckReturnPoint:
mov c, p0.7
        jc InnerSpot1
jnc InnerSpot11

CountCountinus:
inc r0

DigOne:
cjne r0, #1d, DigTwo
   mov r1, a
   Jmp DisplayData

DigTwo:
cjne r0, #2d, DigThree
   mov r2, a
   Jmp DisplayData

DigThree:
cjne r0, #3d, DigFour
   mov r3, a
   Jmp DisplayData

DigFour:
cjne r0, #4d, CheckReturnPoint
        mov r0, #0d
   mov r4, a
Jmp DisplayData

End

Reply

0 Micro Club over 16 years ago in reply to ImPer Westermark

Thanks to support me, ports0-3 are full 8-bit ports.

I m sending my source code please inform me any types of errors

I shell be very thankful to you.

org 00h

;Set up Timer 1
        MOV     IE, #0                  ; Disable all interrupt
        MOV     TMOD, #020h             ; Timer 1: Mode 2 (8-bit reload)
        MOV     TH1, #230d              ; Reload value for 1201, SMOD = 0
        MOV     TL1, #230d              ; Make first time-out correct
        ANL     PCON, #07fh             ; To make SMOD =0

;Set up serial ports
        MOV     SCON, #50h              ; Timer 1 : Mode 1 (vari baud) and set receive enable
        SETB    TR1                             ; Start timer 1
        mov r1, #6d
        mov r2, #91d
        mov r3, #63d
        mov r4, #63d

MainLoop:
setb p0.7

mov r7, #90d
        SubLoop:
        mov r6, #90d
                InnerSpot:
                        jmp DisplayData
                InnerSpot1:
                djnz r6, InnerSpot
        djnz r7, SubLoop

clr p0.7

mov r7, #90d
        SubLoop1:
        mov r6, #90d
                InnerSpot12:
                        jmp DisplayData
                InnerSpot11:
                djnz r6, InnerSpot12
        djnz r7, SubLoop1


jmp MainLoop

DisplayData:
mov C, p2.7
orl C, p0.7


        mov b, r1
   mov p2, b
JNC Skip1
        mov b, #254d
        mov p1, b
Skip1:
                mov b, #255d
           mov p1, b
        mov b, r2
   mov p2, b
JNC Skip2
        mov b, #253d
   mov p1, b
Skip2:
                mov b, #255d
           mov p1, b

        mov b, r3
   mov p2, b
JNC Skip3
        mov b, #251d
   mov p1, b
Skip3:
                mov b, #255d
           mov p1, b

        mov b, r4
   mov p2, b
JNC Skip4
        mov b, #247d
   mov p1, b
Skip4:
                mov b, #255d
           mov p1, b

        jnb RI, CheckReturnPoint
        clr RI
        mov a, sbuf

cjne a, #246d, CountCountinus
        mov r0, #0d

CheckReturnPoint:
mov c, p0.7
        jc InnerSpot1
jnc InnerSpot11

CountCountinus:
inc r0

DigOne:
cjne r0, #1d, DigTwo
   mov r1, a
   Jmp DisplayData

DigTwo:
cjne r0, #2d, DigThree
   mov r2, a
   Jmp DisplayData

DigThree:
cjne r0, #3d, DigFour
   mov r3, a
   Jmp DisplayData

DigFour:
cjne r0, #4d, CheckReturnPoint
        mov r0, #0d
   mov r4, a
Jmp DisplayData

End

Children

0 ²erik malund over 16 years ago in reply to Micro Club

from tyhe above
;Set up serial ports

        MOV     SCON, #50h              ; Timer 1 : Mode 1 (vari baud) and set receive enable
        SETB    TR1                             ; Start timer 1
        mov r1, #6d
        mov r2, #91d
        mov r3, #63d
        mov r4, #63d
MainLoop: